When you check yourself out in front of the mirror at the gym after you've only done a couple sets.
Named after that one person named Aaron we all know who dishes out workout advice and claims to go to gym everyday but is in no way in shape.
Thus you just assume he just goes to the gym to lift once or twice and then spend the rest of the time flexing and admiring his non-existent muscles in the mirror.
Someone who is addicted to obtaining money and building wealth. A money addict and fanatic. Breadheads often work more than one full-time job, and some even participate in illicit activities to "obtain the bread".